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linux/net/ipv6/seg6_local.c
Andrea Mayer 8b532109bf seg6: add support for SRv6 End.DT46 Behavior 
IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and
End.DT46 Behaviors.

The current SRv6 code in the Linux kernel only implements End.DT4 and
End.DT6 which can be used respectively to support IPv4-in-IPv6 and
IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a
single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic.

The proposed End.DT46 implementation is meant to support the decapsulation
of IPv4 and IPv6 traffic coming from a single SRv6 tunnel.
The implementation of the SRv6 End.DT46 Behavior in the Linux kernel
greatly simplifies the setup and operations of SRv6 VPNs.

The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6}
Behaviors implemented so far, because it makes use of a VRF device in
order to force the routing lookup into the associated routing table.

To make the End.DT46 work properly, it must be guaranteed that the routing
table used for routing lookup operations is bound to one and only one VRF
during the tunnel creation. Such constraint has to be enforced by enabling
the VRF strict_mode sysctl parameter, i.e.:

 $ sysctl -wq net.vrf.strict_mode=1

Note that the same approach is used for the SRv6 End.DT4 Behavior and for
the End.DT6 Behavior in VRF mode.

The command used to instantiate an SRv6 End.DT46 Behavior is
straightforward, i.e.:

 $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100.

[1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking
=======================================================================

This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on
the performance of SRv6 End.DT4 and End.DT6 Behaviors.
In order to verify this, we tested the performance of the newly introduced
SRv6 End.DT46 Behavior and compared it with the performance of SRv6
End.DT{4,6} Behaviors, considering both the patched kernel and the kernel
before applying the End.DT46 patch (referred to as vanilla kernel).

In details, the following decapsulation scenarios were considered:

 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel;
 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel;
 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel;
 2.b) SRv6 End.DT4 Behavior on patched kernel;
 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the
      End.DT46 patch);
 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch).

All tests were performed on a testbed deployed on the CloudLab [2]
facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4
GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size
~ 100 bytes.

Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps;
Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps;
Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps;
Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps;
Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps;
Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps;

Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we
observe that the performance degradation incurred in using End.DT46 rather
than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal,
around 0.9% and 1.5%. Such very minimal performance degradation is the
price to be paid if one prefers to use a single tunnel capable of handling
both types of traffic (IPv4 and IPv6).

Comparing the results for End.DT4 and End.DT6 under the patched and the
vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the
End.DT46 patch has no impact on the performance of End.DT4 and End.DT6.

[2] https://www.cloudlab.us

Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-18 11:35:47 -07:00

1955 lines
45 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SR-IPv6 implementation
*
* Authors:
* David Lebrun <david.lebrun@uclouvain.be>
* eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com>
*/
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/net.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/lwtunnel.h>
#include <net/netevent.h>
#include <net/netns/generic.h>
#include <net/ip6_fib.h>
#include <net/route.h>
#include <net/seg6.h>
#include <linux/seg6.h>
#include <linux/seg6_local.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/dst_cache.h>
#include <net/ip_tunnels.h>
#ifdef CONFIG_IPV6_SEG6_HMAC
#include <net/seg6_hmac.h>
#endif
#include <net/seg6_local.h>
#include <linux/etherdevice.h>
#include <linux/bpf.h>
#define SEG6_F_ATTR(i) BIT(i)
struct seg6_local_lwt;
/* callbacks used for customizing the creation and destruction of a behavior */
struct seg6_local_lwtunnel_ops {
int (*build_state)(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack);
void (*destroy_state)(struct seg6_local_lwt *slwt);
};
struct seg6_action_desc {
int action;
unsigned long attrs;
/* The optattrs field is used for specifying all the optional
* attributes supported by a specific behavior.
* It means that if one of these attributes is not provided in the
* netlink message during the behavior creation, no errors will be
* returned to the userspace.
*
* Each attribute can be only of two types (mutually exclusive):
* 1) required or 2) optional.
* Every user MUST obey to this rule! If you set an attribute as
* required the same attribute CANNOT be set as optional and vice
* versa.
*/
unsigned long optattrs;
int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int static_headroom;
struct seg6_local_lwtunnel_ops slwt_ops;
};
struct bpf_lwt_prog {
struct bpf_prog *prog;
char *name;
};
enum seg6_end_dt_mode {
DT_INVALID_MODE = -EINVAL,
DT_LEGACY_MODE = 0,
DT_VRF_MODE = 1,
};
struct seg6_end_dt_info {
enum seg6_end_dt_mode mode;
struct net *net;
/* VRF device associated to the routing table used by the SRv6
* End.DT4/DT6 behavior for routing IPv4/IPv6 packets.
*/
int vrf_ifindex;
int vrf_table;
/* tunneled packet family (IPv4 or IPv6).
* Protocol and header length are inferred from family.
*/
u16 family;
};
struct pcpu_seg6_local_counters {
u64_stats_t packets;
u64_stats_t bytes;
u64_stats_t errors;
struct u64_stats_sync syncp;
};
/* This struct groups all the SRv6 Behavior counters supported so far.
*
* put_nla_counters() makes use of this data structure to collect all counter
* values after the per-CPU counter evaluation has been performed.
* Finally, each counter value (in seg6_local_counters) is stored in the
* corresponding netlink attribute and sent to user space.
*
* NB: we don't want to expose this structure to user space!
*/
struct seg6_local_counters {
__u64 packets;
__u64 bytes;
__u64 errors;
};
#define seg6_local_alloc_pcpu_counters(__gfp) \
__netdev_alloc_pcpu_stats(struct pcpu_seg6_local_counters, \
((__gfp) | __GFP_ZERO))
#define SEG6_F_LOCAL_COUNTERS SEG6_F_ATTR(SEG6_LOCAL_COUNTERS)
struct seg6_local_lwt {
int action;
struct ipv6_sr_hdr *srh;
int table;
struct in_addr nh4;
struct in6_addr nh6;
int iif;
int oif;
struct bpf_lwt_prog bpf;
#ifdef CONFIG_NET_L3_MASTER_DEV
struct seg6_end_dt_info dt_info;
#endif
struct pcpu_seg6_local_counters __percpu *pcpu_counters;
int headroom;
struct seg6_action_desc *desc;
/* unlike the required attrs, we have to track the optional attributes
* that have been effectively parsed.
*/
unsigned long parsed_optattrs;
};
static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
{
return (struct seg6_local_lwt *)lwt->data;
}
static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb, int flags)
{
struct ipv6_sr_hdr *srh;
int len, srhoff = 0;
if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, &flags) < 0)
return NULL;
if (!pskb_may_pull(skb, srhoff + sizeof(*srh)))
return NULL;
srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
len = (srh->hdrlen + 1) << 3;
if (!pskb_may_pull(skb, srhoff + len))
return NULL;
/* note that pskb_may_pull may change pointers in header;
* for this reason it is necessary to reload them when needed.
*/
srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
if (!seg6_validate_srh(srh, len, true))
return NULL;
return srh;
}
static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
{
struct ipv6_sr_hdr *srh;
srh = get_srh(skb, IP6_FH_F_SKIP_RH);
if (!srh)
return NULL;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (!seg6_hmac_validate_skb(skb))
return NULL;
#endif
return srh;
}
static bool decap_and_validate(struct sk_buff *skb, int proto)
{
struct ipv6_sr_hdr *srh;
unsigned int off = 0;
srh = get_srh(skb, 0);
if (srh && srh->segments_left > 0)
return false;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (srh && !seg6_hmac_validate_skb(skb))
return false;
#endif
if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0)
return false;
if (!pskb_pull(skb, off))
return false;
skb_postpull_rcsum(skb, skb_network_header(skb), off);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
if (iptunnel_pull_offloads(skb))
return false;
return true;
}
static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
{
struct in6_addr *addr;
srh->segments_left--;
addr = srh->segments + srh->segments_left;
*daddr = *addr;
}
static int
seg6_lookup_any_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
u32 tbl_id, bool local_delivery)
{
struct net *net = dev_net(skb->dev);
struct ipv6hdr *hdr = ipv6_hdr(skb);
int flags = RT6_LOOKUP_F_HAS_SADDR;
struct dst_entry *dst = NULL;
struct rt6_info *rt;
struct flowi6 fl6;
int dev_flags = 0;
fl6.flowi6_iif = skb->dev->ifindex;
fl6.daddr = nhaddr ? *nhaddr : hdr->daddr;
fl6.saddr = hdr->saddr;
fl6.flowlabel = ip6_flowinfo(hdr);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = hdr->nexthdr;
if (nhaddr)
fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
if (!tbl_id) {
dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags);
} else {
struct fib6_table *table;
table = fib6_get_table(net, tbl_id);
if (!table)
goto out;
rt = ip6_pol_route(net, table, 0, &fl6, skb, flags);
dst = &rt->dst;
}
/* we want to discard traffic destined for local packet processing,
* if @local_delivery is set to false.
*/
if (!local_delivery)
dev_flags |= IFF_LOOPBACK;
if (dst && (dst->dev->flags & dev_flags) && !dst->error) {
dst_release(dst);
dst = NULL;
}
out:
if (!dst) {
rt = net->ipv6.ip6_blk_hole_entry;
dst = &rt->dst;
dst_hold(dst);
}
skb_dst_drop(skb);
skb_dst_set(skb, dst);
return dst->error;
}
int seg6_lookup_nexthop(struct sk_buff *skb,
struct in6_addr *nhaddr, u32 tbl_id)
{
return seg6_lookup_any_nexthop(skb, nhaddr, tbl_id, false);
}
/* regular endpoint function */
static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* regular endpoint, and forward to specified nexthop */
static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
seg6_lookup_nexthop(skb, &slwt->nh6, 0);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
seg6_lookup_nexthop(skb, NULL, slwt->table);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* decapsulate and forward inner L2 frame on specified interface */
static int input_action_end_dx2(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct net *net = dev_net(skb->dev);
struct net_device *odev;
struct ethhdr *eth;
if (!decap_and_validate(skb, IPPROTO_ETHERNET))
goto drop;
if (!pskb_may_pull(skb, ETH_HLEN))
goto drop;
skb_reset_mac_header(skb);
eth = (struct ethhdr *)skb->data;
/* To determine the frame's protocol, we assume it is 802.3. This avoids
* a call to eth_type_trans(), which is not really relevant for our
* use case.
*/
if (!eth_proto_is_802_3(eth->h_proto))
goto drop;
odev = dev_get_by_index_rcu(net, slwt->oif);
if (!odev)
goto drop;
/* As we accept Ethernet frames, make sure the egress device is of
* the correct type.
*/
if (odev->type != ARPHRD_ETHER)
goto drop;
if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev))
goto drop;
skb_orphan(skb);
if (skb_warn_if_lro(skb))
goto drop;
skb_forward_csum(skb);
if (skb->len - ETH_HLEN > odev->mtu)
goto drop;
skb->dev = odev;
skb->protocol = eth->h_proto;
return dev_queue_xmit(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* decapsulate and forward to specified nexthop */
static int input_action_end_dx6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct in6_addr *nhaddr = NULL;
/* this function accepts IPv6 encapsulated packets, with either
* an SRH with SL=0, or no SRH.
*/
if (!decap_and_validate(skb, IPPROTO_IPV6))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto drop;
/* The inner packet is not associated to any local interface,
* so we do not call netif_rx().
*
* If slwt->nh6 is set to ::, then lookup the nexthop for the
* inner packet's DA. Otherwise, use the specified nexthop.
*/
if (!ipv6_addr_any(&slwt->nh6))
nhaddr = &slwt->nh6;
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
seg6_lookup_nexthop(skb, nhaddr, 0);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int input_action_end_dx4(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct iphdr *iph;
__be32 nhaddr;
int err;
if (!decap_and_validate(skb, IPPROTO_IPIP))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
skb->protocol = htons(ETH_P_IP);
iph = ip_hdr(skb);
nhaddr = slwt->nh4.s_addr ?: iph->daddr;
skb_dst_drop(skb);
skb_set_transport_header(skb, sizeof(struct iphdr));
err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
if (err)
goto drop;
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
#ifdef CONFIG_NET_L3_MASTER_DEV
static struct net *fib6_config_get_net(const struct fib6_config *fib6_cfg)
{
const struct nl_info *nli = &fib6_cfg->fc_nlinfo;
return nli->nl_net;
}
static int __seg6_end_dt_vrf_build(struct seg6_local_lwt *slwt, const void *cfg,
u16 family, struct netlink_ext_ack *extack)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
int vrf_ifindex;
struct net *net;
net = fib6_config_get_net(cfg);
/* note that vrf_table was already set by parse_nla_vrftable() */
vrf_ifindex = l3mdev_ifindex_lookup_by_table_id(L3MDEV_TYPE_VRF, net,
info->vrf_table);
if (vrf_ifindex < 0) {
if (vrf_ifindex == -EPERM) {
NL_SET_ERR_MSG(extack,
"Strict mode for VRF is disabled");
} else if (vrf_ifindex == -ENODEV) {
NL_SET_ERR_MSG(extack,
"Table has no associated VRF device");
} else {
pr_debug("seg6local: SRv6 End.DT* creation error=%d\n",
vrf_ifindex);
}
return vrf_ifindex;
}
info->net = net;
info->vrf_ifindex = vrf_ifindex;
info->family = family;
info->mode = DT_VRF_MODE;
return 0;
}
/* The SRv6 End.DT4/DT6 behavior extracts the inner (IPv4/IPv6) packet and
* routes the IPv4/IPv6 packet by looking at the configured routing table.
*
* In the SRv6 End.DT4/DT6 use case, we can receive traffic (IPv6+Segment
* Routing Header packets) from several interfaces and the outer IPv6
* destination address (DA) is used for retrieving the specific instance of the
* End.DT4/DT6 behavior that should process the packets.
*
* However, the inner IPv4/IPv6 packet is not really bound to any receiving
* interface and thus the End.DT4/DT6 sets the VRF (associated with the
* corresponding routing table) as the *receiving* interface.
* In other words, the End.DT4/DT6 processes a packet as if it has been received
* directly by the VRF (and not by one of its slave devices, if any).
* In this way, the VRF interface is used for routing the IPv4/IPv6 packet in
* according to the routing table configured by the End.DT4/DT6 instance.
*
* This design allows you to get some interesting features like:
* 1) the statistics on rx packets;
* 2) the possibility to install a packet sniffer on the receiving interface
* (the VRF one) for looking at the incoming packets;
* 3) the possibility to leverage the netfilter prerouting hook for the inner
* IPv4 packet.
*
* This function returns:
* - the sk_buff* when the VRF rcv handler has processed the packet correctly;
* - NULL when the skb is consumed by the VRF rcv handler;
* - a pointer which encodes a negative error number in case of error.
* Note that in this case, the function takes care of freeing the skb.
*/
static struct sk_buff *end_dt_vrf_rcv(struct sk_buff *skb, u16 family,
struct net_device *dev)
{
/* based on l3mdev_ip_rcv; we are only interested in the master */
if (unlikely(!netif_is_l3_master(dev) && !netif_has_l3_rx_handler(dev)))
goto drop;
if (unlikely(!dev->l3mdev_ops->l3mdev_l3_rcv))
goto drop;
/* the decap packet IPv4/IPv6 does not come with any mac header info.
* We must unset the mac header to allow the VRF device to rebuild it,
* just in case there is a sniffer attached on the device.
*/
skb_unset_mac_header(skb);
skb = dev->l3mdev_ops->l3mdev_l3_rcv(dev, skb, family);
if (!skb)
/* the skb buffer was consumed by the handler */
return NULL;
/* when a packet is received by a VRF or by one of its slaves, the
* master device reference is set into the skb.
*/
if (unlikely(skb->dev != dev || skb->skb_iif != dev->ifindex))
goto drop;
return skb;
drop:
kfree_skb(skb);
return ERR_PTR(-EINVAL);
}
static struct net_device *end_dt_get_vrf_rcu(struct sk_buff *skb,
struct seg6_end_dt_info *info)
{
int vrf_ifindex = info->vrf_ifindex;
struct net *net = info->net;
if (unlikely(vrf_ifindex < 0))
goto error;
if (unlikely(!net_eq(dev_net(skb->dev), net)))
goto error;
return dev_get_by_index_rcu(net, vrf_ifindex);
error:
return NULL;
}
static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb,
struct seg6_local_lwt *slwt, u16 family)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
struct net_device *vrf;
__be16 protocol;
int hdrlen;
vrf = end_dt_get_vrf_rcu(skb, info);
if (unlikely(!vrf))
goto drop;
switch (family) {
case AF_INET:
protocol = htons(ETH_P_IP);
hdrlen = sizeof(struct iphdr);
break;
case AF_INET6:
protocol = htons(ETH_P_IPV6);
hdrlen = sizeof(struct ipv6hdr);
break;
case AF_UNSPEC:
fallthrough;
default:
goto drop;
}
if (unlikely(info->family != AF_UNSPEC && info->family != family)) {
pr_warn_once("seg6local: SRv6 End.DT* family mismatch");
goto drop;
}
skb->protocol = protocol;
skb_dst_drop(skb);
skb_set_transport_header(skb, hdrlen);
return end_dt_vrf_rcv(skb, family, vrf);
drop:
kfree_skb(skb);
return ERR_PTR(-EINVAL);
}
static int input_action_end_dt4(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct iphdr *iph;
int err;
if (!decap_and_validate(skb, IPPROTO_IPIP))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
skb = end_dt_vrf_core(skb, slwt, AF_INET);
if (!skb)
/* packet has been processed and consumed by the VRF */
return 0;
if (IS_ERR(skb))
return PTR_ERR(skb);
iph = ip_hdr(skb);
err = ip_route_input(skb, iph->daddr, iph->saddr, 0, skb->dev);
if (unlikely(err))
goto drop;
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int seg6_end_dt4_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET, extack);
}
static enum
seg6_end_dt_mode seg6_end_dt6_parse_mode(struct seg6_local_lwt *slwt)
{
unsigned long parsed_optattrs = slwt->parsed_optattrs;
bool legacy, vrfmode;
legacy = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE));
vrfmode = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE));
if (!(legacy ^ vrfmode))
/* both are absent or present: invalid DT6 mode */
return DT_INVALID_MODE;
return legacy ? DT_LEGACY_MODE : DT_VRF_MODE;
}
static enum seg6_end_dt_mode seg6_end_dt6_get_mode(struct seg6_local_lwt *slwt)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
return info->mode;
}
static int seg6_end_dt6_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
enum seg6_end_dt_mode mode = seg6_end_dt6_parse_mode(slwt);
struct seg6_end_dt_info *info = &slwt->dt_info;
switch (mode) {
case DT_LEGACY_MODE:
info->mode = DT_LEGACY_MODE;
return 0;
case DT_VRF_MODE:
return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET6, extack);
default:
NL_SET_ERR_MSG(extack, "table or vrftable must be specified");
return -EINVAL;
}
}
#endif
static int input_action_end_dt6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
if (!decap_and_validate(skb, IPPROTO_IPV6))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto drop;
#ifdef CONFIG_NET_L3_MASTER_DEV
if (seg6_end_dt6_get_mode(slwt) == DT_LEGACY_MODE)
goto legacy_mode;
/* DT6_VRF_MODE */
skb = end_dt_vrf_core(skb, slwt, AF_INET6);
if (!skb)
/* packet has been processed and consumed by the VRF */
return 0;
if (IS_ERR(skb))
return PTR_ERR(skb);
/* note: this time we do not need to specify the table because the VRF
* takes care of selecting the correct table.
*/
seg6_lookup_any_nexthop(skb, NULL, 0, true);
return dst_input(skb);
legacy_mode:
#endif
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
seg6_lookup_any_nexthop(skb, NULL, slwt->table, true);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
#ifdef CONFIG_NET_L3_MASTER_DEV
static int seg6_end_dt46_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
return __seg6_end_dt_vrf_build(slwt, cfg, AF_UNSPEC, extack);
}
static int input_action_end_dt46(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
unsigned int off = 0;
int nexthdr;
nexthdr = ipv6_find_hdr(skb, &off, -1, NULL, NULL);
if (unlikely(nexthdr < 0))
goto drop;
switch (nexthdr) {
case IPPROTO_IPIP:
return input_action_end_dt4(skb, slwt);
case IPPROTO_IPV6:
return input_action_end_dt6(skb, slwt);
}
drop:
kfree_skb(skb);
return -EINVAL;
}
#endif
/* push an SRH on top of the current one */
static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
err = seg6_do_srh_inline(skb, slwt->srh);
if (err)
goto drop;
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
/* encapsulate within an outer IPv6 header and a specified SRH */
static int input_action_end_b6_encap(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
skb_reset_inner_headers(skb);
skb->encapsulation = 1;
err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);
if (err)
goto drop;
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states);
bool seg6_bpf_has_valid_srh(struct sk_buff *skb)
{
struct seg6_bpf_srh_state *srh_state =
this_cpu_ptr(&seg6_bpf_srh_states);
struct ipv6_sr_hdr *srh = srh_state->srh;
if (unlikely(srh == NULL))
return false;
if (unlikely(!srh_state->valid)) {
if ((srh_state->hdrlen & 7) != 0)
return false;
srh->hdrlen = (u8)(srh_state->hdrlen >> 3);
if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3, true))
return false;
srh_state->valid = true;
}
return true;
}
static int input_action_end_bpf(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct seg6_bpf_srh_state *srh_state =
this_cpu_ptr(&seg6_bpf_srh_states);
struct ipv6_sr_hdr *srh;
int ret;
srh = get_and_validate_srh(skb);
if (!srh) {
kfree_skb(skb);
return -EINVAL;
}
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
/* preempt_disable is needed to protect the per-CPU buffer srh_state,
* which is also accessed by the bpf_lwt_seg6_* helpers
*/
preempt_disable();
srh_state->srh = srh;
srh_state->hdrlen = srh->hdrlen << 3;
srh_state->valid = true;
rcu_read_lock();
bpf_compute_data_pointers(skb);
ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb);
rcu_read_unlock();
switch (ret) {
case BPF_OK:
case BPF_REDIRECT:
break;
case BPF_DROP:
goto drop;
default:
pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret);
goto drop;
}
if (srh_state->srh && !seg6_bpf_has_valid_srh(skb))
goto drop;
preempt_enable();
if (ret != BPF_REDIRECT)
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
preempt_enable();
kfree_skb(skb);
return -EINVAL;
}
static struct seg6_action_desc seg6_action_table[] = {
{
.action = SEG6_LOCAL_ACTION_END,
.attrs = 0,
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end,
},
{
.action = SEG6_LOCAL_ACTION_END_X,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_x,
},
{
.action = SEG6_LOCAL_ACTION_END_T,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_t,
},
{
.action = SEG6_LOCAL_ACTION_END_DX2,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_OIF),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_dx2,
},
{
.action = SEG6_LOCAL_ACTION_END_DX6,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_dx6,
},
{
.action = SEG6_LOCAL_ACTION_END_DX4,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH4),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_dx4,
},
{
.action = SEG6_LOCAL_ACTION_END_DT4,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
#ifdef CONFIG_NET_L3_MASTER_DEV
.input = input_action_end_dt4,
.slwt_ops = {
.build_state = seg6_end_dt4_build,
},
#endif
},
{
.action = SEG6_LOCAL_ACTION_END_DT6,
#ifdef CONFIG_NET_L3_MASTER_DEV
.attrs = 0,
.optattrs = SEG6_F_LOCAL_COUNTERS |
SEG6_F_ATTR(SEG6_LOCAL_TABLE) |
SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
.slwt_ops = {
.build_state = seg6_end_dt6_build,
},
#else
.attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
#endif
.input = input_action_end_dt6,
},
{
.action = SEG6_LOCAL_ACTION_END_DT46,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
#ifdef CONFIG_NET_L3_MASTER_DEV
.input = input_action_end_dt46,
.slwt_ops = {
.build_state = seg6_end_dt46_build,
},
#endif
},
{
.action = SEG6_LOCAL_ACTION_END_B6,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_b6,
},
{
.action = SEG6_LOCAL_ACTION_END_B6_ENCAP,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_b6_encap,
.static_headroom = sizeof(struct ipv6hdr),
},
{
.action = SEG6_LOCAL_ACTION_END_BPF,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_BPF),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_bpf,
},
};
static struct seg6_action_desc *__get_action_desc(int action)
{
struct seg6_action_desc *desc;
int i, count;
count = ARRAY_SIZE(seg6_action_table);
for (i = 0; i < count; i++) {
desc = &seg6_action_table[i];
if (desc->action == action)
return desc;
}
return NULL;
}
static bool seg6_lwtunnel_counters_enabled(struct seg6_local_lwt *slwt)
{
return slwt->parsed_optattrs & SEG6_F_LOCAL_COUNTERS;
}
static void seg6_local_update_counters(struct seg6_local_lwt *slwt,
unsigned int len, int err)
{
struct pcpu_seg6_local_counters *pcounters;
pcounters = this_cpu_ptr(slwt->pcpu_counters);
u64_stats_update_begin(&pcounters->syncp);
if (likely(!err)) {
u64_stats_inc(&pcounters->packets);
u64_stats_add(&pcounters->bytes, len);
} else {
u64_stats_inc(&pcounters->errors);
}
u64_stats_update_end(&pcounters->syncp);
}
static int seg6_local_input(struct sk_buff *skb)
{
struct dst_entry *orig_dst = skb_dst(skb);
struct seg6_action_desc *desc;
struct seg6_local_lwt *slwt;
unsigned int len = skb->len;
int rc;
if (skb->protocol != htons(ETH_P_IPV6)) {
kfree_skb(skb);
return -EINVAL;
}
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
desc = slwt->desc;
rc = desc->input(skb, slwt);
if (!seg6_lwtunnel_counters_enabled(slwt))
return rc;
seg6_local_update_counters(slwt, len, rc);
return rc;
}
static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
[SEG6_LOCAL_ACTION] = { .type = NLA_U32 },
[SEG6_LOCAL_SRH] = { .type = NLA_BINARY },
[SEG6_LOCAL_TABLE] = { .type = NLA_U32 },
[SEG6_LOCAL_VRFTABLE] = { .type = NLA_U32 },
[SEG6_LOCAL_NH4] = { .type = NLA_BINARY,
.len = sizeof(struct in_addr) },
[SEG6_LOCAL_NH6] = { .type = NLA_BINARY,
.len = sizeof(struct in6_addr) },
[SEG6_LOCAL_IIF] = { .type = NLA_U32 },
[SEG6_LOCAL_OIF] = { .type = NLA_U32 },
[SEG6_LOCAL_BPF] = { .type = NLA_NESTED },
[SEG6_LOCAL_COUNTERS] = { .type = NLA_NESTED },
};
static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int len;
srh = nla_data(attrs[SEG6_LOCAL_SRH]);
len = nla_len(attrs[SEG6_LOCAL_SRH]);
/* SRH must contain at least one segment */
if (len < sizeof(*srh) + sizeof(struct in6_addr))
return -EINVAL;
if (!seg6_validate_srh(srh, len, false))
return -EINVAL;
slwt->srh = kmemdup(srh, len, GFP_KERNEL);
if (!slwt->srh)
return -ENOMEM;
slwt->headroom += len;
return 0;
}
static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
struct nlattr *nla;
int len;
srh = slwt->srh;
len = (srh->hdrlen + 1) << 3;
nla = nla_reserve(skb, SEG6_LOCAL_SRH, len);
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), srh, len);
return 0;
}
static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
int len = (a->srh->hdrlen + 1) << 3;
if (len != ((b->srh->hdrlen + 1) << 3))
return 1;
return memcmp(a->srh, b->srh, len);
}
static void destroy_attr_srh(struct seg6_local_lwt *slwt)
{
kfree(slwt->srh);
}
static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]);
return 0;
}
static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->table != b->table)
return 1;
return 0;
}
static struct
seg6_end_dt_info *seg6_possible_end_dt_info(struct seg6_local_lwt *slwt)
{
#ifdef CONFIG_NET_L3_MASTER_DEV
return &slwt->dt_info;
#else
return ERR_PTR(-EOPNOTSUPP);
#endif
}
static int parse_nla_vrftable(struct nlattr **attrs,
struct seg6_local_lwt *slwt)
{
struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt);
if (IS_ERR(info))
return PTR_ERR(info);
info->vrf_table = nla_get_u32(attrs[SEG6_LOCAL_VRFTABLE]);
return 0;
}
static int put_nla_vrftable(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt);
if (IS_ERR(info))
return PTR_ERR(info);
if (nla_put_u32(skb, SEG6_LOCAL_VRFTABLE, info->vrf_table))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_vrftable(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
struct seg6_end_dt_info *info_a = seg6_possible_end_dt_info(a);
struct seg6_end_dt_info *info_b = seg6_possible_end_dt_info(b);
if (info_a->vrf_table != info_b->vrf_table)
return 1;
return 0;
}
static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]),
sizeof(struct in_addr));
return 0;
}
static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nla;
nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr));
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr));
return 0;
}
static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr));
}
static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]),
sizeof(struct in6_addr));
return 0;
}
static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nla;
nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr));
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr));
return 0;
}
static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr));
}
static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]);
return 0;
}
static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->iif != b->iif)
return 1;
return 0;
}
static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]);
return 0;
}
static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->oif != b->oif)
return 1;
return 0;
}
#define MAX_PROG_NAME 256
static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = {
[SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, },
[SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING,
.len = MAX_PROG_NAME },
};
static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1];
struct bpf_prog *p;
int ret;
u32 fd;
ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_BPF_PROG_MAX,
attrs[SEG6_LOCAL_BPF],
bpf_prog_policy, NULL);
if (ret < 0)
return ret;
if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME])
return -EINVAL;
slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL);
if (!slwt->bpf.name)
return -ENOMEM;
fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]);
p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL);
if (IS_ERR(p)) {
kfree(slwt->bpf.name);
return PTR_ERR(p);
}
slwt->bpf.prog = p;
return 0;
}
static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nest;
if (!slwt->bpf.prog)
return 0;
nest = nla_nest_start_noflag(skb, SEG6_LOCAL_BPF);
if (!nest)
return -EMSGSIZE;
if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id))
return -EMSGSIZE;
if (slwt->bpf.name &&
nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name))
return -EMSGSIZE;
return nla_nest_end(skb, nest);
}
static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (!a->bpf.name && !b->bpf.name)
return 0;
if (!a->bpf.name || !b->bpf.name)
return 1;
return strcmp(a->bpf.name, b->bpf.name);
}
static void destroy_attr_bpf(struct seg6_local_lwt *slwt)
{
kfree(slwt->bpf.name);
if (slwt->bpf.prog)
bpf_prog_put(slwt->bpf.prog);
}
static const struct
nla_policy seg6_local_counters_policy[SEG6_LOCAL_CNT_MAX + 1] = {
[SEG6_LOCAL_CNT_PACKETS] = { .type = NLA_U64 },
[SEG6_LOCAL_CNT_BYTES] = { .type = NLA_U64 },
[SEG6_LOCAL_CNT_ERRORS] = { .type = NLA_U64 },
};
static int parse_nla_counters(struct nlattr **attrs,
struct seg6_local_lwt *slwt)
{
struct pcpu_seg6_local_counters __percpu *pcounters;
struct nlattr *tb[SEG6_LOCAL_CNT_MAX + 1];
int ret;
ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_CNT_MAX,
attrs[SEG6_LOCAL_COUNTERS],
seg6_local_counters_policy, NULL);
if (ret < 0)
return ret;
/* basic support for SRv6 Behavior counters requires at least:
* packets, bytes and errors.
*/
if (!tb[SEG6_LOCAL_CNT_PACKETS] || !tb[SEG6_LOCAL_CNT_BYTES] ||
!tb[SEG6_LOCAL_CNT_ERRORS])
return -EINVAL;
/* counters are always zero initialized */
pcounters = seg6_local_alloc_pcpu_counters(GFP_KERNEL);
if (!pcounters)
return -ENOMEM;
slwt->pcpu_counters = pcounters;
return 0;
}
static int seg6_local_fill_nla_counters(struct sk_buff *skb,
struct seg6_local_counters *counters)
{
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_PACKETS, counters->packets,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_BYTES, counters->bytes,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_ERRORS, counters->errors,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
return 0;
}
static int put_nla_counters(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct seg6_local_counters counters = { 0, 0, 0 };
struct nlattr *nest;
int rc, i;
nest = nla_nest_start(skb, SEG6_LOCAL_COUNTERS);
if (!nest)
return -EMSGSIZE;
for_each_possible_cpu(i) {
struct pcpu_seg6_local_counters *pcounters;
u64 packets, bytes, errors;
unsigned int start;
pcounters = per_cpu_ptr(slwt->pcpu_counters, i);
do {
start = u64_stats_fetch_begin_irq(&pcounters->syncp);
packets = u64_stats_read(&pcounters->packets);
bytes = u64_stats_read(&pcounters->bytes);
errors = u64_stats_read(&pcounters->errors);
} while (u64_stats_fetch_retry_irq(&pcounters->syncp, start));
counters.packets += packets;
counters.bytes += bytes;
counters.errors += errors;
}
rc = seg6_local_fill_nla_counters(skb, &counters);
if (rc < 0) {
nla_nest_cancel(skb, nest);
return rc;
}
return nla_nest_end(skb, nest);
}
static int cmp_nla_counters(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
/* a and b are equal if both have pcpu_counters set or not */
return (!!((unsigned long)a->pcpu_counters)) ^
(!!((unsigned long)b->pcpu_counters));
}
static void destroy_attr_counters(struct seg6_local_lwt *slwt)
{
free_percpu(slwt->pcpu_counters);
}
struct seg6_action_param {
int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
/* optional destroy() callback useful for releasing resources which
* have been previously acquired in the corresponding parse()
* function.
*/
void (*destroy)(struct seg6_local_lwt *slwt);
};
static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
[SEG6_LOCAL_SRH] = { .parse = parse_nla_srh,
.put = put_nla_srh,
.cmp = cmp_nla_srh,
.destroy = destroy_attr_srh },
[SEG6_LOCAL_TABLE] = { .parse = parse_nla_table,
.put = put_nla_table,
.cmp = cmp_nla_table },
[SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4,
.put = put_nla_nh4,
.cmp = cmp_nla_nh4 },
[SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6,
.put = put_nla_nh6,
.cmp = cmp_nla_nh6 },
[SEG6_LOCAL_IIF] = { .parse = parse_nla_iif,
.put = put_nla_iif,
.cmp = cmp_nla_iif },
[SEG6_LOCAL_OIF] = { .parse = parse_nla_oif,
.put = put_nla_oif,
.cmp = cmp_nla_oif },
[SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf,
.put = put_nla_bpf,
.cmp = cmp_nla_bpf,
.destroy = destroy_attr_bpf },
[SEG6_LOCAL_VRFTABLE] = { .parse = parse_nla_vrftable,
.put = put_nla_vrftable,
.cmp = cmp_nla_vrftable },
[SEG6_LOCAL_COUNTERS] = { .parse = parse_nla_counters,
.put = put_nla_counters,
.cmp = cmp_nla_counters,
.destroy = destroy_attr_counters },
};
/* call the destroy() callback (if available) for each set attribute in
* @parsed_attrs, starting from the first attribute up to the @max_parsed
* (excluded) attribute.
*/
static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed,
struct seg6_local_lwt *slwt)
{
struct seg6_action_param *param;
int i;
/* Every required seg6local attribute is identified by an ID which is
* encoded as a flag (i.e: 1 << ID) in the 'attrs' bitmask;
*
* We scan the 'parsed_attrs' bitmask, starting from the first attribute
* up to the @max_parsed (excluded) attribute.
* For each set attribute, we retrieve the corresponding destroy()
* callback. If the callback is not available, then we skip to the next
* attribute; otherwise, we call the destroy() callback.
*/
for (i = 0; i < max_parsed; ++i) {
if (!(parsed_attrs & SEG6_F_ATTR(i)))
continue;
param = &seg6_action_params[i];
if (param->destroy)
param->destroy(slwt);
}
}
/* release all the resources that may have been acquired during parsing
* operations.
*/
static void destroy_attrs(struct seg6_local_lwt *slwt)
{
unsigned long attrs = slwt->desc->attrs | slwt->parsed_optattrs;
__destroy_attrs(attrs, SEG6_LOCAL_MAX + 1, slwt);
}
static int parse_nla_optional_attrs(struct nlattr **attrs,
struct seg6_local_lwt *slwt)
{
struct seg6_action_desc *desc = slwt->desc;
unsigned long parsed_optattrs = 0;
struct seg6_action_param *param;
int err, i;
for (i = 0; i < SEG6_LOCAL_MAX + 1; ++i) {
if (!(desc->optattrs & SEG6_F_ATTR(i)) || !attrs[i])
continue;
/* once here, the i-th attribute is provided by the
* userspace AND it is identified optional as well.
*/
param = &seg6_action_params[i];
err = param->parse(attrs, slwt);
if (err < 0)
goto parse_optattrs_err;
/* current attribute has been correctly parsed */
parsed_optattrs |= SEG6_F_ATTR(i);
}
/* store in the tunnel state all the optional attributed successfully
* parsed.
*/
slwt->parsed_optattrs = parsed_optattrs;
return 0;
parse_optattrs_err:
__destroy_attrs(parsed_optattrs, i, slwt);
return err;
}
/* call the custom constructor of the behavior during its initialization phase
* and after that all its attributes have been parsed successfully.
*/
static int
seg6_local_lwtunnel_build_state(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
struct seg6_action_desc *desc = slwt->desc;
struct seg6_local_lwtunnel_ops *ops;
ops = &desc->slwt_ops;
if (!ops->build_state)
return 0;
return ops->build_state(slwt, cfg, extack);
}
/* call the custom destructor of the behavior which is invoked before the
* tunnel is going to be destroyed.
*/
static void seg6_local_lwtunnel_destroy_state(struct seg6_local_lwt *slwt)
{
struct seg6_action_desc *desc = slwt->desc;
struct seg6_local_lwtunnel_ops *ops;
ops = &desc->slwt_ops;
if (!ops->destroy_state)
return;
ops->destroy_state(slwt);
}
static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
struct seg6_action_param *param;
struct seg6_action_desc *desc;
unsigned long invalid_attrs;
int i, err;
desc = __get_action_desc(slwt->action);
if (!desc)
return -EINVAL;
if (!desc->input)
return -EOPNOTSUPP;
slwt->desc = desc;
slwt->headroom += desc->static_headroom;
/* Forcing the desc->optattrs *set* and the desc->attrs *set* to be
* disjoined, this allow us to release acquired resources by optional
* attributes and by required attributes independently from each other
* without any interference.
* In other terms, we are sure that we do not release some the acquired
* resources twice.
*
* Note that if an attribute is configured both as required and as
* optional, it means that the user has messed something up in the
* seg6_action_table. Therefore, this check is required for SRv6
* behaviors to work properly.
*/
invalid_attrs = desc->attrs & desc->optattrs;
if (invalid_attrs) {
WARN_ONCE(1,
"An attribute cannot be both required AND optional");
return -EINVAL;
}
/* parse the required attributes */
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
if (desc->attrs & SEG6_F_ATTR(i)) {
if (!attrs[i])
return -EINVAL;
param = &seg6_action_params[i];
err = param->parse(attrs, slwt);
if (err < 0)
goto parse_attrs_err;
}
}
/* parse the optional attributes, if any */
err = parse_nla_optional_attrs(attrs, slwt);
if (err < 0)
goto parse_attrs_err;
return 0;
parse_attrs_err:
/* release any resource that may have been acquired during the i-1
* parse() operations.
*/
__destroy_attrs(desc->attrs, i, slwt);
return err;
}
static int seg6_local_build_state(struct net *net, struct nlattr *nla,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[SEG6_LOCAL_MAX + 1];
struct lwtunnel_state *newts;
struct seg6_local_lwt *slwt;
int err;
if (family != AF_INET6)
return -EINVAL;
err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla,
seg6_local_policy, extack);
if (err < 0)
return err;
if (!tb[SEG6_LOCAL_ACTION])
return -EINVAL;
newts = lwtunnel_state_alloc(sizeof(*slwt));
if (!newts)
return -ENOMEM;
slwt = seg6_local_lwtunnel(newts);
slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
err = parse_nla_action(tb, slwt);
if (err < 0)
goto out_free;
err = seg6_local_lwtunnel_build_state(slwt, cfg, extack);
if (err < 0)
goto out_destroy_attrs;
newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
newts->headroom = slwt->headroom;
*ts = newts;
return 0;
out_destroy_attrs:
destroy_attrs(slwt);
out_free:
kfree(newts);
return err;
}
static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
seg6_local_lwtunnel_destroy_state(slwt);
destroy_attrs(slwt);
return;
}
static int seg6_local_fill_encap(struct sk_buff *skb,
struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
struct seg6_action_param *param;
unsigned long attrs;
int i, err;
if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
return -EMSGSIZE;
attrs = slwt->desc->attrs | slwt->parsed_optattrs;
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
if (attrs & SEG6_F_ATTR(i)) {
param = &seg6_action_params[i];
err = param->put(skb, slwt);
if (err < 0)
return err;
}
}
return 0;
}
static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
unsigned long attrs;
int nlsize;
nlsize = nla_total_size(4); /* action */
attrs = slwt->desc->attrs | slwt->parsed_optattrs;
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_SRH))
nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH4))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH6))
nlsize += nla_total_size(16);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_IIF))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_OIF))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_BPF))
nlsize += nla_total_size(sizeof(struct nlattr)) +
nla_total_size(MAX_PROG_NAME) +
nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_LOCAL_COUNTERS)
nlsize += nla_total_size(0) + /* nest SEG6_LOCAL_COUNTERS */
/* SEG6_LOCAL_CNT_PACKETS */
nla_total_size_64bit(sizeof(__u64)) +
/* SEG6_LOCAL_CNT_BYTES */
nla_total_size_64bit(sizeof(__u64)) +
/* SEG6_LOCAL_CNT_ERRORS */
nla_total_size_64bit(sizeof(__u64));
return nlsize;
}
static int seg6_local_cmp_encap(struct lwtunnel_state *a,
struct lwtunnel_state *b)
{
struct seg6_local_lwt *slwt_a, *slwt_b;
struct seg6_action_param *param;
unsigned long attrs_a, attrs_b;
int i;
slwt_a = seg6_local_lwtunnel(a);
slwt_b = seg6_local_lwtunnel(b);
if (slwt_a->action != slwt_b->action)
return 1;
attrs_a = slwt_a->desc->attrs | slwt_a->parsed_optattrs;
attrs_b = slwt_b->desc->attrs | slwt_b->parsed_optattrs;
if (attrs_a != attrs_b)
return 1;
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
if (attrs_a & SEG6_F_ATTR(i)) {
param = &seg6_action_params[i];
if (param->cmp(slwt_a, slwt_b))
return 1;
}
}
return 0;
}
static const struct lwtunnel_encap_ops seg6_local_ops = {
.build_state = seg6_local_build_state,
.destroy_state = seg6_local_destroy_state,
.input = seg6_local_input,
.fill_encap = seg6_local_fill_encap,
.get_encap_size = seg6_local_get_encap_size,
.cmp_encap = seg6_local_cmp_encap,
.owner = THIS_MODULE,
};
int __init seg6_local_init(void)
{
/* If the max total number of defined attributes is reached, then your
* kernel build stops here.
*
* This check is required to avoid arithmetic overflows when processing
* behavior attributes and the maximum number of defined attributes
* exceeds the allowed value.
*/
BUILD_BUG_ON(SEG6_LOCAL_MAX + 1 > BITS_PER_TYPE(unsigned long));
return lwtunnel_encap_add_ops(&seg6_local_ops,
LWTUNNEL_ENCAP_SEG6_LOCAL);
}
void seg6_local_exit(void)
{
lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
}
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